Study procedures: When the patient is admitted at the Stollery Children's Hospital and the necessity of heart surgery with CPB is established, patients will be screened for eligibility. Written informed consent will be asked. After consent, patient demographics and baseline variables will be recorded. Eligible patients will be randomly assigned in a 1:1 ratio to the intervention group or the control group. Randomization will be done by a computer based program at the Epidemiology Coordinating and Research Centre (EPICORE) to facilitate the procedure and to ensure allocation concealment. As a patient qualifies for the trial, a study number and a randomization number will be assigned.